forearm muscles: attachments, nerve supply and actions

Question 1

cfo meaning

Answer 1

Common Flexor Origin
The bony landmark where the common flexor origin attaches is the medial epicondyle of the humerus

Question 2

ceo meaning

Answer 2

Common Extensor Origin
The bony landmark where the common extensor origin attaches is the lateral epicondyle of the humerus

Question 3

anterior forearm muscles action and nerve supply

Answer 3

Chief action of this compartment is to flex the wrist and digits and pronate the forearm
All muscles in this group are innervated by the median nerve, except for the FCU and the medial half of the FDP which are supplied by the ulnar nerve

Question 4

anterior forearm muscles

Answer 4

Superficial Muscle Group
pronator teres (PT)
flexor carpi radialis (FCR)
palmaris longus (PL)
flexor carpi ulnaris (FCU)

Intermediate Muscle Group
flexor digitorum superficialis (FDS)

Deep Muscle Group (do not cross the elbow joint)
flexor digitorum profundus (FDP)
flexor pollicis longus (FPL)
pronator quadratus (PQ)

Question 5

proximal and distal attachments, nerve supply and actions of pronator teres

Answer 5

PA- Humeral head: Medial epicondyle of humerus (CFO)
Ulnar head: Coronoid process of ulna

DA- Lateral surface of the radius, middle third

N/S- Median nerve

A- Pronates the forearm and flexes the elbow joint

Question 6

proximal and distal attachments, nerve supply and actions of Flexor Carpi Radialis

Answer 6

PA- Medial epicondyle of the humerus (CFO)
DA- Base of the 2nd metacarpal (anteriorly)
N/S- Median nerve
A- Flexes and radially deviates the wrist joint

Question 7

proximal and distal attachments, nerve supply and actions of palmaris longus

Answer 7

PA- Medial epicondyle of the humerus (CFO)
DA- Flexor retinaculum and palmar aponeurosis
N/S- Median nerve
A- Flexes the wrist joint and tenses the palmar aponeurosis

Question 8

proximal and distal attachments, nerve supply and actions of Flexor Carpi Ulnaris

Answer 8

PA-
Humeral head: Medial epicondyle of the humerus (CFO)
Ulnar head: Olecranon process of the ulna
DA- Pisiform, hook of the hamate & 5th metacarpal (anteriorly)
N/S- Ulnar nerve
A- Flexes and ulnar deviates the wrist joint

Question 9

proximal and distal attachments, nerve supply and actions of Flexor Digitorum Superficialis

Answer 9

PA- Medial epicondyle of the humerus (CFO) & the anterior surface of the radius
DA- Middle phalanges of digits 2-5
N/S- Median nerve
A- Flexes digits 2-5 at the proximal interphalangeal joints (PIPs) and metacarpophalangeal joints (MCPs)

Question 10

proximal and distal attachments, nerve supply and actions of Flexor Digitorum Profundus

Answer 10

PA- Anterior surface of the ulna and the interosseous membrane
DA-
Lateral half: distal phalanges of digits 2&3
Medial half: distal phalanges digits 4&5
N/S-
Lateral half: Median nerve
Medial half: Ulnar nerve
A- Flexes digits 2-5 at the distal interphalangeal joints (DIPs)

Question 11

proximal and distal attachments, nerve supply and actions of Flexor Pollicis Longus

Answer 11

PA- Anterior surface of the radius and the interosseous membrane
DA- Distal phalanx of the thumb (anteriorly)
N/S- Median nerve
A- Flexes thumb at interphalangeal joint and metacarpophalangeal (MCP) joint

Question 12

proximal and distal attachments, nerve supply and actions of Pronator Quadratus

Answer 12

PA- Distal quarter of anterior surface of ulna
DA- Distal quarter of anterior surface of radius
N/S- Median nerve
A- Pronates the forearm

Question 13

posterior forearm muscles action and nerve supply

Answer 13

Chief action of this compartment is to extend the wrist and digits and supinate the forearm
All muscles in this group are innervated by the radial nerve

Question 14

posterior forearm muscles

Answer 14

Superficial Muscle Group
Brachioradialis
Extensor carpi radialis longus (ECRL)
Extensor carpi radialis brevis (ECRB)
Extensor digitorum (ED)
Extensor digiti minimi (EDM)
Extensor carpi ulnaris (ECU)

Deep Muscle Group
Supinator
Abductor pollicis longus (APL)
Extensor pollicis brevis (EPB)
Extensor pollicis longus (EPL)
Extensor indicis (EI)

Question 15

proximal and distal attachments, nerve supply and actions of brachioradialis

Answer 15

PA- Lateral supracondylar ridge of the humerus
DA- Lateral surface of the distal radius
N/S- Radial nerve
A- Flexes the elbow joint when it is in the mid-prone position

Question 16

proximal and distal attachments, nerve supply and actions of Extensor Carpi Radialis Longus

Answer 16

PA- Lateral supracondylar ridge of the humerus
DA- Base of the 2nd metacarpal (posteriorly)
N/S- Radial nerve
A- Extends and radially deviates the wrist joint

Question 17

proximal and distal attachments, nerve supply and actions of Extensor Carpi Radialis brevis

Answer 17

PA- Lateral epicondyle of the humerus (CEO)
DA- Base of the 3rd metacarpal (posteriorly)
N/S- Radial nerve
A- Extends and radially deviates the wrist joint

Question 18

proximal and distal attachments, nerve supply and actions of Extensor digitorum

Answer 18

PA- Lateral epicondyle of the humerus (CEO)
DA- Extensor expansions of digits 2-5
N/S- Radial nerve
A- Extends digits 2-5 at the metacarpophalangeal (MCP) joint & interphalangeal joints

Question 19

proximal and distal attachments, nerve supply and actions of Extensor Digiti Minimi

Answer 19

PA- Lateral epicondyle of the humerus (CEO)
DA- Extensor expansion of the 5th digit
N/S- Radial nerve
A- Extends 5th digit at the metacarpophalangeal (MCP) & interphalangeal joints

Question 20

proximal and distal attachments, nerve supply and actions of Extensor Carpi Ulnaris

Answer 20

PA- Lateral epicondyle of the humerus (CEO) and the posterior border of the ulna
DA- Base of the 5th metacarpal (posteriorly)
N/S- Radial nerve
A- Extends and ulnar deviates the wrist joint

Question 21

proximal and distal attachments, nerve supply and actions of supinator

Answer 21

PA- Lateral epicondyle of the humerus (CEO) & the supinator crest of the ulna
DA- Lateral, posterior & anterior surfaces of the proximal radius
N/S- Radial nerve
A- Supinates the forearm

Question 22

proximal and distal attachments, nerve supply and actions of Abductor Pollicis Longus

Answer 22

PA- Posterior surface of the ulna, radius and interosseous membrane
DA- Base of the 1st metacarpal
N/S- Radial nerve
A- Abducts the thumb and extends it at the carpometacarpal joint

Question 23

proximal and distal attachments, nerve supply and actions of Extensor Pollicis Brevis

Answer 23

PA- Posterior surface of the radius and interosseous membrane
DA- Proximal phalanx of thumb (posteriorly)
N/S- Radial nerve
A- Extends thumb at metacarpophalangeal joint (MCP) and carpometacarpal joint

Question 24

proximal and distal attachments, nerve supply and actions of Extensor Pollicis Longus

Answer 24

PA- Posterior surface of the ulna and interosseous membrane
DA- Distal phalanx of thumb (posteriorly)
N/S- Radial nerve
A- Extends the thumb at the interphalangeal joint, metacarpophalangeal (MCP) joint & carpometacarpal joint

Question 25

proximal and distal attachments, nerve supply and actions of Extensor Indicis

Answer 25

PA- Posterior surface of the ulna and interosseous membrane DA- Extensor expansion of 2nd digit N/S- Radial nerve A- Extends 2nd digit at the metacarpophalangeal (MCP) joint & interphalangeal joints